Figure 2.

Light Modulates Spikes Recorded in Bipolar Cells in Retinal Slices

(A–F) Examples of voltage spikes and oscillations recorded in the soma of six different bipolar cells with qualitatively distinct responses. In each panel, the black traces show three responses to the same 500 ms step of light (the scale bars represent 10 mV). The blue trace shows the average response to eight presentations of the stimulus where injection of a hyperpolarizing current, resulting in a voltage drop of −5 mV, prevented spike generation (the scale bars represent 2 mV). The currents used ranged between −2 and −20 pA in different cells. Examples of cells filled with Alexa 488 are shown in (A and D). The schematic insets illustrate the morphological classification of each cell (see also Figure S2). (A and B) are fast ON cells. (C) is a sustained OFF cell. (D) is a delayed ON cell. (E) is a transient OFF cell. (F) is a cell that generated damped oscillations at both light onset and offset.

(G) Voltage responses of two bipolar cells to 500 ms steps of current injection, without (black) and with (red) creatine phosphate in the intracellular solution.

(H) The average amplitude of a spike as a function of time after beginning whole-cell recording, normalized to the first (collected results from 44 cells). The error bars represent one standard error of the mean (S.E.M.). See also Figure S2.